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| United States Patent |
6,200,354
|
|
Collins
, et al.
|
March 13, 2001
|
Dyeing of textiles
Abstract
A method of dyeing cellulosic fibers or fabrics using pre-metallized acid
dye by pretreating the fabric with a cationic agent having a plurality of
cationic centers and optionally after treating the dyed material with a
cationic polymer is disclosed. The cationic polymer is desirably a
polyquaternary amine material especially a poly(DADMAC) or
polyvinylpyridine. Material dyed by the method has a "washed out"
appearance similar to fabrics dyed using the "Jarofast" process, but the
availability of a wide range of pre-metallized dyes gives a wider color
range, and the method enables a wider range of substrates to be dyed
successfully, including lyocell fiber materials e.g. those sold under
Courtauld's trademark "Tencel" and blend/union materials with polyamides,
easier processing and superior wash and light fastness.
| Inventors:
|
Collins; Geoffrey William (Greasby, GB);
Burkinshaw; Stephen Martin (Collingham, GB);
Gordon; Roy (Middlesbrough, GB)
|
| Assignee:
|
Imperial Chemical Industries PLC (GB)
|
| Appl. No.:
|
379006 |
| Filed:
|
August 23, 1999 |
Foreign Application Priority Data
| Current U.S. Class: |
8/554; 8/555; 8/556; 8/606; 8/685; 8/686; 8/918; 8/920; 8/921; 8/930 |
| Intern'l Class: |
D06P 001/52; D06P 003/60; D06P 005/22 |
| Field of Search: |
8/554,606,918,555,556,685,686,920,921,930
|
References Cited
U.S. Patent Documents
| 4806126 | Feb., 1989 | Sternberger et al.
| |
| 4864007 | Sep., 1989 | Schleusener.
| |
| 5024674 | Jun., 1991 | Prelini et al.
| |
| Foreign Patent Documents |
| 44 10 866 | Oct., 1995 | DE.
| |
| 1 053 672 | Feb., 1954 | FR.
| |
| 2 146 545 | Mar., 1973 | FR.
| |
| 1 053 172 | Dec., 1966 | GB.
| |
| 1 067 102 | May., 1967 | GB.
| |
Primary Examiner: Einsmann; Margaret
Attorney, Agent or Firm: Pillsbury, Madison & Sutro, LLP Intellectual Property Grp
Parent Case Text
This is a continuation under 35 U.S.C. Section 120 of International
application Ser. No. PCT/GB98/00497 filed on Feb. 18, 1998 which
application designates the U.S.
Claims
What is claimed is:
1. A method of making a dyed cellulosic fibrous material, which comprises:
1. treating the material with a cationic polymeric pretreatment agent
having a plurality of cationic centres and a degree of cationicity
(expressed as cationic centres per units of molecular weight) of at least
1 cationic centre per 750 Daltons;
2. dyeing the material with a pre-metallized acid dye; and
3. optionally treating the material with a cationic polymer.
2. A method as claimed in claim 1 wherein the cellulosic fibrous material
contains from 30 to 100% of natural, synthetic or regenerated cellulosic
fibres or blends of such materials.
3. A method as claimed in claim 2 wherein the natural cellulosic fibrous
material is cotton, flax, jute, hemp and/or ramie; and the synthetic or
regenerated cellulosic fibrous material is rayon and/or a lyocell
material.
4. A method as claimed in claim 1 wherein the fibrous material is a blend
of one or more cellulosic fibres with non-cellulosic fibrous material.
5. A method as claimed in claim 4 wherein the fibrous non-cellulosic
material is a polyethylene terephthalate polymer or related copolymer,
and/or a wool, silk and/or synthetic polyamide fibre.
6. A method as claimed in claim 1 wherein the polymeric pretreatment agent
contains poly-quaternary nitrogen centres which are of the formula
--N.sup.+ (R).sub.3 where each R is an alkyl group; or where two of the
groups R together with the nitrogen atom bearing them form a 5 or 6
membered heterocyclic ring; or --N.sup.+ (R').sub.2 -- where the groups R'
are as defined for R above and the other bonds directly or indirectly link
into the polymer chain optionally via or 5- or 6-membered ring; and/or
aromatic quaternary nitrogen centres.
7. A method as claimed in claim 1 wherein the polymeric pretreatment agent
has a degree of cationicity (expressed as cationic centres per units of
molecular weight) of from 1 cationic centre per 150 Daltons to 1 cationic
centre per 500 Daltons.
8. A method as claimed in claim 1 wherein the pre-metallized acid dye is a
1:1 pre-metallized acid dyes, a 2:1 pre-metallized acid non-ionic
solubilised dye, a 2:1 pre-metallized acid asymmetrical monosulphonated
dye, or a 2:1 pre-metallized acid symmetrical
di-sulphonated/dicarboxylated dye.
9. A method as claimed in claim 1 wherein the material is subjected to a
post dyeing treatment with a cationic agent having a plurality of cationic
centres.
10. A method as claimed in claim 1 wherein the dyed material is subjected
to further deliberate washing or enzyme treatment.
11. A method as claimed in claim 1 wherein the cellulosic material is a
cotton, rayon or lyocell material and the pre-metallized acid dye is a 2:1
pre-metallized acid asymmetrical monosulphonated dye.
Description
This information relates to the dyeing of textiles, and in particular to
the dyeing of pre-treated cellulosic textiles using pre-metallized acid
dyes.
It is well known that cellulosic textiles can be dyed with reactive,
direct, sulphur, vat and azoic dyes. Other classes of dyestuff,
particularly acid dyes, are relatively ineffective in dyeing cellulose
substrates because their chemistry does not make them readily substantive
to the cellulose fibres.
A recent development in the dyeing of cellulose substrates is a proprietary
process known as the Jarofast process, which involves the use of a
cationic pretreatment before dyeing with an anionic solubilised sulphur
dye, followed by a treatment which removes some of the dye, typically a
washing or enzyme treatment step, to produce dyed textile having a "washed
out" appearance. This appearance is very fashionable and popular
particularly for cotton products such as jeans and related products. The
products of this process have a desirable appearance, but the dyeing is
not very wash fast and has poor light fastness. Whilst the Jarofast
process can be successfully applied to cotton and other similar natural
cellulosic fibres, it is less successful in dyeing regenerated cellulosics
and does not work at all well on rayon or lyocell materials such as
`Tencel` fabrics made from Courtaulds lyocell fibre.
The present invention is based on our discovery that by using a suitable
pretreatment of the cellulosic fibres, pre-metallized acid dyes can be
applied to cotton and similar cellulosic substrates, including regenerated
cellulosics such as rayon and especially lyocell fibre materials such as
`Tencel` fabrics, to give well dyed products with good wash fastness and
which can give dyed fabric with good "washed out" appearance, which can be
enhanced by suitable post-dyeing treatment. Further benefits are that in
washing in normal use the level of staining of adjacent fabrics is very
much lower than is obtained with fabrics treated by the Jarofast process.
Accordingly, the present invention provides a method of making a dyed
cellulosic fibrous material, which comprises the steps of:
1 treating the material with a cationic agent having a plurality of
cationic centres;
2 dyeing the material with a pre-metallized acid dye; and
3 optionally treating the material with a cationic polymer.
The substrate treated in this invention is described as a fibrous
cellulosic textile material. By this we mean that the substrate is
cellulosic or contains, typically, from 30 to 100% fibres of, cellulosic
material. Typical cellulosic fibre materials which can be included in such
fabrics include natural cellulosic fibrous material such as cotton, flax,
jute, hemp and ramie, and synthetic or regenerated cellulosic fibrous
material such as rayon particularly viscose and acetate rayon and solvent
spun materials, particularly where the solvent is N-methylmorpholine oxide
(NMMO) which are often referred to as lyocell materials and in particular
the lyocell fibre from Courtaulds and the fabrics made from such fibre
sold under the Courtaulds trade name `Tencel`. The cellulosic fibre
material can be a blend on more than one type of cellulosic fibre or a
blend of fibres of cellulosic fibres with non-cellulosic materials and in
particular includes blends of cellulosic fibres, particularly cotton,
rayon and especially lyocell, fibre with polyester, particularly
polyethylene terephthalate polymer or related copolymer, fibre, or with
polyamide fibres, including wool, silk and synthetic polyamides such as
nylon. The textile can be a woven (including knitted) or non-woven
textile, but will usually be a clothing textile material.
The polymeric pretreatment agent used in the invention is cationic and such
materials are referred to as cationic polymeric pretreatment agents. The
cationic polymeric pretreatment agents are polymer including a plurality
of cationic centres and are usually made by polymerisation of monomers
containing cationic or potentially cationic centres. Desirably the
cationic centres are quaternary nitrogen centres which may be aliphatic
quaternary ammonium groups or quaternary aromatic nitrogen centres. The
quaternary nitrogen centre may be present as such in the polymeric agent
or may be present under application conditions or may be generated in situ
after application to the textile. Examples of cationic quaternary nitrogen
centres which can be present in the polymeric pretreatment agent include:
--N.sup.+ (R).sub.3 where each R is an alkyl group particularly a C.sub.1
to C.sub.4 alkyl e.g. methyl group, although one or more of the R groups
may be a longer chain alkyl group e.g. a C.sub.6 to C.sub.18 alkyl group,
or where two of the groups R together with the nitrogen atom bearing them
form a heterocyclic ring, particularly a 5 or 6 membered ring, which may
include further hetero atoms, such as piperidine, tetrahydropyrrole,
piperazine and morpholine rings, which may themselves be further
substituted as in N-alkyl e.g. methyl, piperazine rings; or one of the R
groups may be a group, typically an alkylene group, linking to another,
usually nitrogen, site in the polymer or to another polymer chain; or
--N.sup.+ (R').sub.2 -- where the groups R' are as defined for R above and
the other bonds directly or indirectly link into the polymer chain
optionally via a ring, usually a 5- or 6-membered ring; and aromatic
quaternary nitrogen centres such as pyridinium.
The degree of cationicity (expressed as cationic centres per units of
molecular weight) is generally at least 1 cationic, particularly
quaternary nitrogen centre, per 1500 Daltons (D), desirably at least 1
cationic centre per 1000 D, more usually at least 1 cationic centre per
750 D and with the most effective polymers we have tested at least 1
cationic centre per 500 D. The maximum concentration of cationic centres
is about 1 per 120 D, desirably not more than about 1 per 150D. (Relative
molecular weights are expressed including chloride as a counter ion for
cationic centres.)
Expressed as cationic centres per monomer residue in the polymer, the
polymer typically has at least about 1 cationic centre per 20, more
usually at least about 1 cationic centre per 10, and desirably at least
about 1 cationic centre per 5, monomer residues in the polymer. The upper
limit is typically 1 cationic centre per monomer residue.
Examples of cationic polymeric pretreatment agents include polymers of
diallyldimethylammonium chloride (which polymerises to give a repeat unit
including cyclic, 5- and/or 6membered ring including dimethyl ammonium
groups)--conveniently referred to under the abbreviation poly-DADMAC
(diallyldimethylammonium chloride) such as is available under the trade
name Matexil FC-ER from ICI Surfactants, quaternised (co-)polymers of
vinylpyridines, such as 4-vinylpyridine, copolymers of dimethylamine and
epi-chlorohydrin such as is available under the trade name Fixogene CXF
from ICI Surfactants and copolymers of diallyldimethylammonium and
diallyl-N-2-hydroxy-3chloro-propylamine (or its protonated ammonium
derivative) and copolymers having repeat units of diallylmethylamine (or
its protonated ammonium derivative) and
diallyl-N-methyl-N-2-hydroxyl3-chloropropylammonium. The charge balancing
anions for the quaternary ammonium groups are typically halide,
particularly chloride, ions. These latter two copolymers are capable of
crosslinking or similar reactions involving the chloride substituent on
the propyl group and other nitrogen centres.
The cationic polymeric pretreatment agents used in this invention typically
have molecular weights of from 5 to 50 kD and more desirably from 10 to 30
kD.
The use of cationic polymeric pretreatment agents has the advantage that
they are strongly substantive to the cellulosic fibres, and are thus
readily applied to the textiles, and typical pre-metallized acid dyes are
substantive to the treated cellulosic textile material. This can
substantially ease application of the dyes to the cellulosic textile
material for example reducing or eliminating the need for the use of salts
to encourage substantivity and making it possible to operate to high dye
solution exhaustion.
The cationic polymeric pretreatment agents used in this invention typically
have molecular weights of from 5 to 50 kD and more desirably from 10 to 30
kD.
The pre-treatment of the fabric with the polymeric pretreatment agent can
be carried out by immersing the fabric in an aqueous solution or
dispersion of the pretreatment agent at temperatures of up to about
100.degree. C., particularly from about 20 to about 80.degree. C., for a
period of up to 2 hours, particularly from 15 minutes to 1 hour, e.g. from
20 to 30 minutes. Temperatures of about 40.degree. C. are particularly
appropriate for cotton and similar natural cellulosic materials although
higher temperatures may be used. Temperatures of about 60 to about
80.degree. C. are particularly appropriate for synthetic cellulosic
materials such as rayon and especially lyocell materials, because the
polymer is generally more crystalline than natural cellulosics, although
again higher temperatures may be used.
The amount of the pretreatment agent in the treatment bath is desirably
from 0.1 to 3%, particularly 0.25 to 2% and especially from 0.5 to 1%, by
weight of 100% active pretreatment agent based on the dry weight of the
fabric being pretreated. (Note--the pretreatment agents are typically
supplied as 30 to 35% active aqueous solutions and this will be taken into
account in determining the amount of the particular product used.) The
liquor ratio (the ratio of the treatement/dye solution used to dry cloth
weight) for pretreatment is typically from 5 to 25 desirably about 10. The
pre-treatment solution is typically at or near neutral e.g. pH 6 to 7, but
may be higher e.g. up to abut 11 and in particular 8 to 11, where rayon or
lyocell materials are being treated.
The pretreatment can also be carried out by padding at ambient temperature
using concentrations and pH values similar to those described above to
give pick up typically about 70 to 150% by weight based on the dry fibre
weight with padding, followed by drying typically at from about 80 to
about 150.degree. C., more usually from about 80 to about 120.degree. C.
The pre-metallized acid dyes used in this invention are acid dyes including
a chelated metal, which is usually a multivalent transition metal such as
chromium, cobalt, copper, zinc and iron, but usually chromium. The metal
is typically chelated to oxygen atoms derived from phenolic groups in the
organic acid dye molecule and usually also to azo nitrogen atoms via
dative bonds. The pre-metallized acid dye molecules may carry an overall
electrical charge depending on the valency (oxidation state) of the metal
and the number and type of chelating sites in the organic acid dye.
Pre-metallized acid dyes fall into four general categories:
1 1:1 pre-metallized acid dyes--in which each pre-metallized acid dye
molecule includes one chelated metal centre and one organic acid dye
molecule, typically including at least one sulphonic acid group, which may
be neutralised with a suitable cation such as an alkali metal cation e.g.
sodium. Usually, the acid dye molecule will have insufficient chelating
centres to fully occupy the available chelating power of the metal and the
remaining ligands are provided by the water solvent. An Example is Colour
Index (Cl) Acid Brown 144:
##STR1##
2 2:1 pre-metallized acid non-ionic solubilised dyes--in which each
pre-metallized acid dye molecule includes one chelated metal centre and
two organic dye molecules, usually the same, which in the pre-metallized
acid dye carries no free acid substituents. The dye molecules are the only
ligands for the chelated metal. In order to ensure that the pre-metallized
acid dye is sufficiently water soluble, the organic dye part of the
molecule will include hydrophilic substituents such as sulphonamido
groups. An Example is Colour Index (Cl) Acid Black 60:
##STR2##
3 2:1 pre-metallized acid asymmetrical monosulphonated dyes--in which each
pre-metallized acid dye molecule includes one chelated metal centre and
two, different organic dye molecules. One of the dye molecules includes a
sulphonic acid group and the other usually is non acidic. Examples include
Neutrichrome S dyes such as:
##STR3##
4 2:1 pre-metallized acid symmetrical di-sulphonated/dicarboxylated
dyes--in which each pre-metallized add dye molecule includes one chelated
metal centre and two, identical organic dye molecules. Each of the dye
molecules includes a sulphonic and/or carboxylic acid group Examples
include Acidol M dyes such as:
##STR4##
Although each of these types of pre-metallized acid dyes can be used in
this invention, we have obtained particularly good results with 2:1
pre-metallized acid asymmetrical monosulphonated dyes and the use of these
dyes forms a specific and advantageous aspect of the invention. Suitable
specific dyestuffs include those of the Lanasyn S (Sandoz now Clairant)
range including Lanasyn Olive Green S4GL (Cl Acid Green 106), Lanasyn
Yellow S-2GL (Cl Acid Yellow 235) and Lanasyn Navy S-BL (Cl Acid Blue
296), the Lanacron S (Ciba) range including Lanacron Red SG (Cl Acid Red
315), and Lanacron Grey SB (Cl Acid Black 207) and the Neutrilan S range
(Compton & Knowles) such as Neutrilan Rubine S-2R, Neutrilan Orange SR and
Neutrilan Navy S-B.
The conditions of dyeing will depend on the specific nature of the
pre-metallized acid dye although in general we have successfully used
typical conditions for the dyeing of wool with pre-metallized acid dyes.
Typically these conditions are dyeing at the boil i.e. at or near
100.degree. C., at mildly acid pH typically in the range 5 to 7, at a
concentration corresponding to 0.1 to 5% of dye based on the weight of the
dry fibre at a liquor ratio of from 2 to 25 more commonly about 10. In any
particular case, the amount of dye used, and possibly the concentration of
dye in the dyebath and thus the amount applied to the textile, will depend
on the dye itself and the desired intensity of dyeing.
After dyeing it is desirable to remove any unbound pre-metallized acid dye
from the cellulosic textile material. This has not proved difficult and
simple washing in water has proved effective, particularly as the
pre-metallized acid dyes exhaust readily onto the pre-treated cellulosic
textile material.
After dyeing the cellulosic textile material can be further treated with a
cationic polymer. The cationic polymer used for such a post treatment will
generally be of the same type as the cationic polymeric pretreatment
agents as described above, referred to in this context as cationic
polymeric post-treatment agents. Similarly, the treatment conditions,
concentrations and amounts are within the general and specific ranges set
out above for the cationic polymeric pretreatment agents. The cationic
polymeric post-treatment agents are substantive to the cellulosic textile
material and we believe that they form a coating or layer over the dye on
the cellulosic textile material and this can further improve the wash
fastness of the dyeing and may reduce any tendency of the pre-metallized
acid dye to migrate in washing onto other co-washed materials. The
treatment with cationic polymeric post-treatment agents will typically be
carried out after post-dyeing washing. If a cationic polymeric
post-treatment agent including a group reactive to other parts of the
cationic polymeric post-treatment agents or to the cationic polymeric
pretreatment agent or the cationic nucleophilic polymeric pretreatment
agent is used, it is possible to generate higher molecular weight species
by linking, crosslinking and polymerisation. This may further enhance the
wash fastness of the dyed fabric. An example of such reactive cationic
polymeric post-treatment agents are copolymers having repeat units of
diallylmethylamine (or its protonated ammonium derivative) and
diallyl-2-hydroxy3chloropropyl amine (or its protonated ammonium
derivative) or repeat units of diallylmethylamine (or its protonated
ammonium derivative) and
diallyl-N-methyl-N-2-hydroxyl-3-chloropropylammonium. These latter two
copoplymers may undergo crosslinking and similar reactions involving the
chloride substituent on the propyl group and other nitrogen centres.
The dyed fabrics can, if desired, be subjected to further deliberate
washing or enzyme treatment to enhance the `washed out` appearance.
Using the pretreatment step according to the invention, we have
successfully obtained good dyed products having good wash and light
fastness and good i.e. little, staining of adjacent fabrics in washing.
The results are generally at least as good as those obtained using the
Jarofast system. The optional post dyeing treatment with cationic
polymeric post-treatment agents can further improve the wash and reduce
staining of adjacent fabrics in washing. The ability to use pre-metallized
acid dyes to give good wash fastness (even if in the context of producing
"faded" coloured products) has the benefit that the light fastness of the
dyes is much better than is typically obtained using the sulphur dyes used
in the Jarofast process.
The substrates that can be dyed include not just cotton (as in the Jarofast
system) but other cellulosic textile materials, including rayons and
lyocell materials including `Tencel` fabrics, that have proved difficult
to dye satisfactorily previously.
The increased substantivity of pre-metallized acid dyes to cellulosic
textile materials obtained in the present invention, makes it possible to
dye mixed or blended fabrics with pre-metallized acid dyes. In particular,
the pretreatment enables union fabrics of cellulosic fibres, particularly
cotton, rayons and lyocell materials, with polyamide fibres such as wool,
silk and nylon, to be dyed relatively easily and uniformly. This
possibility forms a specific aspect of the invention which accordingly
includes a method of dyeing a blend or union fabric containing cellulosic
fibres, particularly of cotton rayon or, and especially, lyocell, and
polyamide fibres particularly of wool, silk or nylon, which includes the
steps of:
1 treating the material with a polymeric pretreatment agent having a
plurality of cationic centres;
2 dyeing the material with a pre-metallized acid dye; and
3 optionally treating the material with a cationic polymer.
A further advantage of this invention is that many of the environmental
difficulties associated with conventional cellulosic dyeing processes can
be mitigated or avoided. For example, conventional cellulose reactive
dyeing processes generate large amounts of highly coloured effluents
containing high concentrations of electrolyte (up to 100 g.l.sup.-1) and
alkali. The present process does not generate such effluents, because
salts, such as NaCl, are not needed to drive exhaustion of the dye onto
the substrate, the pre-metallized acid dyes are substantive to the
pre-treated cellulosic textile materials and readily dye to high levels of
exhaustion without adding salts, with some pre-metallized acid dyes we
have achieved 100% exhaustion of the dye bath. Where the pre-metallized
acid dyes do not exhaust fully, it is possible to recycle the dyebath
content as the bath contains only dye and water at the start and end of
the dyeing cycle. The dyeing process is itself simple, requiring no costly
and time consuming wash off procedures.
The following Examples illustrate the invention, all parts and percentages
are by weight unless otherwise stated.
Materials
Dyes
Lanasyn S dyes ex Sandoz/Clairant
Lanasyn Olive Green S-4GL CI Acid Green 106
Lanasyn Yellow S-2GL CI Acid Yellow 235
Lanasyn Navy S-BL CI Acid Blue 296
Lanacron ex Ciba
Lanacron Red SG (CI Acid Red 315)
Lanacron Grey SB (CI Acid Black 207)
Neutrilan S dyes ex Compton and Knowles
Neutrilan Rubine S-2R
Neutrilan Navy S-B
Cationic polymeric pretreatment agents
PT1 Matexil FC-ER a poly(DADMAC) cationic polymer ex ICI
Surfactants
PT2 Fixogene CXF a copolymer of dimethylamine and epi-
chlorohydrin ex ICI Surfactants
PT3 a copolymer of diallyldimethylammonium and diallyl-2-hydroxy-3-
chloropropylammonium
Cationic polymeric post-dyeing treatment agents
AT1 Matexil FC-ER poly(DADMAC) cationic polymer solution (35%
active solids) ex ICI Surfactants
AT2 Fixogene CXF cationic polymer (reaction product of
dimethylamine and epi-chlorohydrin) solution
(50% active solids) ex ICI Surfactants
AT3 a copolymer of diallyldimethylammonium and diallyl-2-hydroxy-3-
chloropropylammonium
In the pre- and post-treatment polymers the counter-anion was chloride.
Pretreatment
On cotton the pretreatment was carried out by immersing samples of scoured,
bleached, FBA free woven cotton (150 g.m.sup.-2) in an aqueous solution of
the pretreatment agent at 2% (of pretreatment agent as supplied) on the
dry fabric weight at a liquor ratio L:R of 10:1, at 40 to 50.degree. C.
for 30 minutes at pH 6 to 7.
On lyocell fabric (`Tencel` fabric made from Courtaulds lyocell fibre) the
pretreatment was carried out by immersing samples of the fabric (190
g.m.sup.-2) in an aqueous solution of the pretreatment agent at 2% (of
pretreatment agent as supplied) on the dry fabric weight, and further
containing 1 g.l.sup.-1 Na.sub.2 CO.sub.3, at a liquor ratio L:R of 10:1,
at 60.degree. C. for 30 minutes. The higher temperature and alkali were
used to aid penetration of the inherently more closely packed structure of
the lyocell fibre.
On the blends with other, particularly polyamide fibres, the pretreatment
was carried out by immersing samples of the fabrics in an aqueous solution
of the pretreatment agent at 2% (of pretreatment agent as supplied) on the
dry fabric weight at a liquor ratio L:R of 10:1, at 50.degree. C. for 30
minutes at a pH of about 7.
Dyeing
The pretreated fabric was wetted out and immersed in the dyebath which
contained only dye and water at pH 6 to 7 to give a L:R of 10:1. Dyeing
was commenced at room temperature and the temperature was raised to 95 to
98.degree. C. and held at this temperature for 60 minutes. The dyed fabric
was rinsed with cold running water until clear, to remove loosely held
surface dye, then allowed to dry. For comparison, dyeings were also
carried out on blank (non-pretreated) samples.
Post-dyeing Treatment (Aftertreatment)
When carried out, aftertreatment on all fabrics was carried out by
immersing the dyed samples in an aqueous solution of the aftertreatment
agent (as supplied) at 2% (of aftertreatment agent as supplied) on the dry
fabric weight at a liquor ratio L:R of i 10:1, at 40 to 50.degree. C. for
30 minutes. For aftertreatment agents AT1, and AT2 the pH used was 6 to 7;
for aftertreatment agent AT3 the pH used was 10 to 11 (adjusted with about
2 ml (30% aqueous NaOH solution).l.sup.-1 (aftertreatment bath). The
samples were subsequently rinsed in cold water and dried.
Test Methods
Wash Fastness
Wash fastness was assessed using the ISO C06/A2S: Colour fastness to
domestic and commercial laundering (40.degree. C.) test. The test was
carried out on samples (10 cm.times.4 cm) of the dyed substrate under
test, stapled to a 4 cm wide piece of standard SDC Multifibre DW adjacent
(including secondary acetate, cotton, nylon, polyester, acrylic, wool).
Assessment of the change in shade and staining of adjacents was made with
the appropriate 9 point grey scales (high scores good).
Colour Measurement
Dyed samples were measured instrumentally. The colorimetric variables L*,
a* and b* were measured and colour strength (K/S) was calculated by
computer from the reflectance at the wavelength of maximum absorption
using the formula:
K/S=(1-R).sup.2 /2R where R is % reflectance.
Light Fastness
Light fastness data was measured by a standard accelerated fading test, ISO
B02: Colour fastness to artificial light: Xenon arc fading lamp test
Alkaline Perspiration Fastness
Alkaline perspiration fastness was measured by the ISO E04 alkaline
perspiration fastness test.
EXAMPLE 1
This Example illustrates the dyeing of Cl Acid Green 106 on cotton samples.
The details of the pre- and after-treatments, Wash Fastness and
colorimetric data are included in Table 1 below. These data show that
pretreatment increases the colour intensity (because the uptake of the dye
is greatly improved), improves wash fastness and reduces adjacent staining
of the dyeings. The more intense colour obtained from pretreatment with
PT2 probably arises from the higher solids of the treatment agent as
supplied by the manufacturer. Aftertreatment does not have a negative
effect on colour strength or shade change, confirming the visual
assessment made during the experiment. The wash fastness testing shows
that some colour loss occurs during washing but with virtually no adjacent
staining. In all cases aftertreatment reduced the amount of colour loss
suffered during washing.
TABLE 1
Pre- After-
treatment treatment shade adjacent Colorimetric data
Sample matl % matl % change staining L* a* b*
K/S
1C -- -- -- -- * * 68.55 -9.81 11.48 0.9
1.1 PT1 2 -- -- 3-3/4 4/5-5 43.17 -11.72 14.72 5.60
1.2 PT1 2 AT1 2 3/4-4 5 42.71 -11.47 14.57
5.78
1.3 PT1 2 AT2 2 3/4 5 42.24 -11.53 14.43
5.80
1.4 PT1 2 AT3 2 4-4/5 5 42.59 -11.37 14.36
5.73
1.5 PT2 2 -- -- 2-2/3 4/5-5 42.00 -11.30 14.38 6.05
1.6 PT2 2 AT1 2 3/4 5 41.84 -11.01 14.06
6.01
1.7 PT2 2 AT2 2 2/3-3 5 41.55 -11.07 13.99
6.06
1.8 PT2 2 AT3 2 4/5 5 41.84 -11.32 14.18
5.97
*the dyeing on the untreated cloth was too weak to generate meaningful wash
fastness data.
EXAMPLE 2
This Example illustrates the dyeing of Cl Acid Red 315, Cl Acid Yellow 235,
Cl Acid Black 207 and Cl Acid Blue 296 on cotton samples. The details of
the pre- and after-treatments and wash fastness and colorimetric data are
set out in Table 2 below. From these data it is clear that the
pretreatment is very effective in enhancing substantivity of the dye on
the fabric without the use of salts in the dyebath. In the tests using Cl
Acid Yellow 235 and Cl Acid Black 207 the dye baths were almost completely
exhausted (even though no steps had been taken to optimise the system to
seek full exhaustion). The application of an aftertreatment resulted in
very little if any colour loss from the samples, the results were
comparable to those in Example 1 for Cl Acid Green 106, and had no effect
on the shade. Wash fastness testing gave results broadly similar to those
of Example 1 Cl Acid Green 106; the aftertreatment reduced the colour loss
from the samples and also reduced the staining of adjacent multifibre
samples.
TABLE 2
Pre- After-
treatment treatment shade adjacent staining colorimetric
data
Sample matl % matl % change cotton nylon wool L*
a* b* K/S
Cl Acid Red 315
2C.1 -- -- 59.72 32.57
10.00 1.96
2.1.1 PT1 2 -- -- 3 2/3 3-3/4 4 36.38 32.73
13.74 9.89
2.1.2 PT1 2 AT1 2 3/4 3 3/4-4 4/5
2.1.3 PT1 2 AT3 2 4 3-3/4 4 4/5
2.1.4 PT2 2 -- -- 2/3 2/3 3-3/4 3/4-4 35.34 33.60
14.47 10.93
2.1.5 PT2 2 AT1 2 3/4 3 3/4 4
2.1.6 PT2 2 AT3 2 4 3/4 4 4/5
Cl Acid Yellow 235
2C.2 -- -- 76.09 10.10
46.03 2.17
2.2.1 PT1 2 -- -- 3 4/5 3/4 4-4/5 63.65 17.87
54.92 7.23
2.2.2 PT1 2 AT1 2 3/4 4/5 4-4/5 4/5
2.2.3 PT1 2 AT3 2 3/4-4 5 4/5 4/5
2.2.4 PT2 2 -- -- 2-2/3 4/5 3-3/4 4 65.40 17.96
55.46 6.54
2.2.5 PT2 2 AT1 2 3/4-4 4/5 4 4/5
2.2.6 PT2 2 AT3 2 4 5 4/5 4/5
Cl Acid Black 207
2C.3 -- -- 51.78 -1.80
4.42 1.85
2.3.1 PT1 2 -- -- 3/4 4-4/5 3/4 5 29.10 -1.26
-2.59 8.55
2.3.2 PT1 2 AT1 2 4 4/5 4 5
2.3.3 PT1 2 AT3 2 4 4/5 4/5 5
2.3.4 PT2 2 -- -- 3/4 4 3-3/4 5 27.93 -0.38
-1.79 9.09
2.3.5 PT2 2 AT1 2 4 4/5 4 5
2.3.6 PT2 2 AT3 2 4 4/5 4/5 5
Cl Acid Blue 296
2.C.4 -- -- 60.79 -1.17
-9.54 1.06
2.4.1 PT1 2 -- -- 3/4 4-4/5 3/4 5 26.74 0.24
-11.30 11.34
2.4.2 PT1 2 AT1 2 4 4/5 4 5
2.4.3 PT1 2 AT3 2 4 4/5 4/5 5
2.4.4 PT2 2 -- -- 3/4 4 3-3/4 5 25.14 0.51
-10.58 12.53
2.4.5 PT2 2 AT1 2 4 4/5 4 5
2.4.6 PT2 2 AT3 2 4 4/5 4/5 5
EXAMPLE 3
Samples of dyed fabrics produced in Examples 1 and 2 were tested for Light
Fastness and Alkaline Perspiration Fastness and the results are set out in
Table 3 below. These data show that the process of the invention provides
dyeings with good Light Fastness and good Alkali Perspiration Fastness.
Similar trends to wash fastness can be seen in that with Cl Acid Red 315
the overall fastness is slightly lower.
TABLE 3
Light Akaline Perspiration Fastness
Fastness shade adjacent staining
Sample Dye rating change cotton nylon wool
1.1 CI Acid Green 106 6-7 -- -- -- --
2.1.1 CI Acid Red 315 5 4/5 3/4 4 4
2.2.1 CI Acid Yellow 235 6-7 5 4-4/5 4-4/5 5
2.3.1 CI Acid Black 207 6-7 5 4/5 4/5 5
2.4.1 CI Acid Blue 296 6-7 5 4/5 4/5 5
EXAMPLE 4
This Example illustrates the dyeing of lyocell fibre `Tencel` fabric with
pre-metallized acid dyes. The fabric was pretreated with agent PT1 and
aftertreatment as set out in Table 4 below. Fastness and colorimetric data
are included in Table 4. These data show that the lyocell fibre was
successfully dyed by the method of this invention and dyeings of
comparable colour strengths to those on cotton were achieved. The general
trends in wash fastness are also similar to those on cotton, with the
fastness on `Tencel` being slightly higher all round than on cotton. We
believe that this is because the molecules in the lyocell fibres are more
closely packed than those in cotton. Correspondingly we believe this is
why lyocell fibre material is more difficult to dye and may explain why
the Jarofast system is ineffective. (The large non-reduced molecules of
the solubilised sulphur dyes used in the Jarofast system cannot penetrate
into the fibre, so they remain on the surface and are subsequently easily
removed during washing.) The improved wash fastness is even more
pronounced following aftertreatment; we believe that the pre-metallized
acid dye is further insolubilised by complexation with the cationic sites
in the cationic polymeric post-treatment agent. The Light Fastness ratings
of the dyes on the lyocell fibre material are generally slightly higher
than their counterparts on cotton.
TABLE 4
Wash Fastness
Pre- After- adjacent Light
treatment treatment shade staining Fast- colorimetric
data
Sample matl % matl % change cotton nylon ness L*
a* b* K/S
Cl Acid Green 106
5.1.1 PT1 2 -- -- 4/5 4/5-5 5
5.1.2 PT1 2 AT1 2 5 5 5 7 43.78
-14.16 17.59 6.28
5.1.3 PT1 2 AT3 2 5 5 5
Cl Acid Red 315
5.2.1 PT1 2 -- -- 3/4 2/3 3-3/4
5.2.2 PT1 2 AT1 2 4 3 3/4 5/6 39.65
37.21 13.5 8.93
5.2.3 PT1 2 AT3 2 4 3/4 4
Cl Acid Yellow 235
5.3.1 PT1 2 -- -- 3/4-4 4-4/5 3/4-4
5.3.2 PT1 2 AT1 2 4/5 5 4-4/5 7 63.73
16.42 57.22 8.25
5.3.3 PT1 2 AT3 2 4/5 5 4/5
Cl Acid Black 207
5.4.1 PT1 2 -- -- 3/4 4-4/5 3/4
5.4.2 PT1 2 AT1 2 4 4/5 4 7 31.91
-2.18 -3.27 7.15
5.4.3 PT1 2 AT3 2 4 4/5 4-4/5
Cl Acid Blue 296
5.5.1 PT1 2 -- -- 4/5 4/5 3/4
5.5.2 PT1 2 AT1 2 4/5 4/5 4 7 28.38
-1.02 -14.74 11.22
5.5.3 PT1 2 AT3 2 4/5 5 4/5
EXAMPLE 5
This Example illustrates the dyeing of viscose/wool and lyocell/wool union
fabrics with pre-metallized acid dyes. Samples of 50:50 lyocell/wool and
wool/viscose intimate fibre blend fabrics were pretreated and dyed with Cl
Acid Black 207 as described above. Information on the pretreatment and
Wash Fastness and colorimetric data are given in Table 5 below.
TABLE 5
adjacent
Pre- staining
treatment shade cot- colorimetric data
Sample matl % change ton nylon L* a* b* K/S
lyocell/
wool
7C.1 -- -- 4/5-5 4/5-5 4-4/5 30.42 0.05 -2.66 7.24
7.1 PT1 2 4/5 4/5 3/4-4 24.23 -0.75 -2.9 12.21
L/W
viscose/
wool
7C.2 -- 4/5 4/5-5 4/5 38.13 -0.19 -2.17 4.16
7.2 PT1 2 4/5 4/5 3/4-4 5.32 -1.3 -3.48 11.58
V/W
These data clearly showed the effect of the pretreatment:
In the samples which were not pretreated, the wool portion dyed
successfully, whilst the lyocell or viscose only stained--the resultant
dyeings were clearly mottled. In the samples that had been pretreated the
colour was far more uniform and had a deeper shade.
The dye baths for all these samples were 100% exhausted (with or without
pretreatment) showing how efficient the dyes are for colouring wool. The
Wash Fastness ratings of the dyeings were very similar to those of the
cotton and `Tencel` fabric dyeings in previous Examples. The appearance of
reduced numerical Fastness ratings for the pretreated samples arises from
the much greater colour depth achieved on the cellulosic portion of the
blend in these samples. (It is well known that pre-metallized acid dyes
possess high fastness on wool, as can be seen from the data on the
non-pretreated sample fastness data in Table 6, in which only the wool
portion was dyed.)
EXAMPLE 6
The dyeings of Example 5 on fibre blend fabrics were extended to other
fabrics and other dyes. Fibre blend fabrics were made up with the
following materials: velour (nylon/cotton), cotton/silk, linen/silk and
hemp/cotton/wool (this fabric was made using a relatively crude blend of
the different fibres). The fabrics were pretreated with PT1 at described
above and samples were then dyed with Neutrilan Rubine S-2R and Neutrilan
Navy S-B respectively. The dyeing conditions were that the temperature was
raised to 98.degree. C. at a rate of 2.degree. C. min.sup.-1 and held at
98.degree. C. for 60 minutes. The dyed fabrics were briefly washed, rinsed
and dried. The pretreated fabrics dyed to give uniform dyeings of a deeper
shade than non-pretreated controls. For the first three mixed fibre
fabrics, the fibre blends were intimate enough that the control dyeings
looked uniform, but the dyeings on the pretreated fabrics were of a much
deeper shade. For the hemp/cotton/wool mixed fabric, the control dyeing
looked mottled, whereas the dyeings on the pretreated fabric were uniform
and of a much deeper shade. Wash Fastness testing gave similar results to
those on viscose/wool and lyocell/wool mixtures described in Example 5.
After treatment with AT1 further improved the Wash Fastness of these
samples.
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